1. Field of the Invention
The invention relates to a motor vehicle door lock arrangement having a lock latch, a detent pawl and an electrical detent pawl drive, with control switches for triggering the electric detent pawl drive, with a power supply connection and with a lock mechanism with at least one mechanical opening lever which acts on the detent pawl, and in the normal case, the detent pawl can be activated only by the electrical detent pawl drive, and in the emergency case, by the mechanical opening lever.
2. Description of Related Art
Motor vehicle door lock arrangements of the above described type have been known for some time and are generally referred to as so-called "electric locks" (see, for example, published European Patent Application EP-A-0 589 158, and published German Patent Application DE-A-195 45 722). In an electric lock, there is always the problem that provisions must be made for a power failure or other malfunction of the electrical detent pawl drive. It must be ensured that, even in this emergency, the motor vehicle door can be opened.
There are different approaches to taking into account the aforementioned emergency. There is, for example, the equipment of the respective individual motor vehicle door lock arrangement can be provided with its own emergency power supply which is independent of the motor vehicle electrical system. Then, in the case of an emergency, switching from the motor vehicle electrical system to the emergency power supply takes place (see EP-A-0 584 499). This requires a switching process, and in addition, backing-up the emergency power supply on each door lock means with the necessity of always ensuring its serviceability. Another approach is a type of dynamo function for an emergency by which by repeated actuation of the mechanical opening lever, for example, from the outside handle, charges a storage device for electrical energy (e.g., a battery, capacitor, etc.) to such a level that the emergency function occurs. Another approach is a permanently serviceable mechanical redundancy, with which a mechanical opening actuation can be produced from a lock cylinder or other location (see, published German Patent Applications DE-A-195 45 722 and DE-A-195 01 493.).
Another approach is to provide the electrical detent pawl drive with a mechanical energy storage device which, when the power supply fails or upon some other malfunction of the electrical detent pawl drive, automatically actuates the mechanical opening lever (see, European Patent Application EP-A-0 589 158). A solenoid is provided with an armature which, in the normal case, is continuously spring pre-tensioned by the mechanical energy storage device, and when the current fails, is shifted into the emergency position by the spring pretension (DE-A-196 31 869)